#define _CRT_SECURE_NO_WARNINGS
typedef struct TreeNode TreeNode;
bool isSameTree(struct TreeNode* p, struct TreeNode* q) {
    if (p == NULL && q == NULL)
    {
        return true;
    }
    if (p == NULL || q == NULL)
    {
        return false;
    }
    if (p->val != q->val)
    {
        return false;
    }
    return isSameTree(p->left, q->right) && isSameTree(p->right, q->left);
}

bool isSymmetric(struct TreeNode* root)
{
    return isSameTree(root->left, root->right);
}